The present invention relates to an apparatus for ripping seams and hems or for otherwise separating two pieces of cloth which have been sewn together.
Cutting tools for removing seams and hems are well known in the prior art; however, all such tools suffer from two major disadvantages: they are slow, and they tend to cut the material or cloth rather than the seam. For example, the Kehetian Patent, U.S. Pat. No. 1,660,340, shows a typical seam cutting device consisting of a two piece holder for grasping a razor blade or similar cutting edge, and a guide finger to hook into the seam or hem and bring the stitch into contact with the blade where it can be severed. Due to its cross-sectional geometry, however, the '340 device can only cut very slowly. In cross section, this device can be viewed as a series of flat plates, one of which is the blade edge, wherein the plates grasp the blade between them. With such an arrangement it is likely that the user will tear the cloth if an attempt is made to move the cutter rapidly along the seam. The problem is that the seam is presented with the essentially vertical walls of the plates which tend to bunch the material or fabric in towards the blade. This increases the risk that if the cutter is moved too swiftly, the material itself will be engaged by the blade and cut.
A similar device having essentially the same deficiency is shown in Baltuch U.S. Pat. No. 2,254,199. The device of the '199 patent is even less desirable for the cutting of seams and the like because of its inclined guide member and blade, which form an oblique angle to the seam and make it difficult to align the cutter for movement in a straight line.
This problem is alleviated to a degree in Pauli, U.S. Pat. No. 2,688,187, which shows a holder utilizing a razor blade as a cutting tool and a V-shaped notch in one side of the holder for ripping seams. The Pauli device, however, suffers from the problems previously encountered with the seam cutters in both the '340 and '199 patents, in that the cross-sectional shape of the cutter is essentially rectangular which does not serve to efficiently separate the cloth from the stitch prior to engagement by the blade. In addition, in the '187 device, the blade occupies most of the transverse dimension exposed by the notch. Having the blade lie so far forwardly of the vertex of the notch will also cause the blade to sever the material as well as the stitch.
The blade is recessed much further into the notch in Applebay U.S. Pat. No. 630,792. Deeply recessing the blade also presents a problem where simple forward pressure of the handle is the sole means used for cutting the stitch. Ordinarily, recessing the blade far into the notch will result in the need for greater forward pressure in order to sever the stitch. To compensate, Applebay uses reciprocating motion of the blade to cut the stitch, which is awkward and slow. The Applebay device also utilizes a handle which is perpendicular to the edge of the blade. It is much more difficult to cut a stitch in this manner since the handle must be aligned longitudinally with the stitch.
Another approach is shown in Klamroth U.S. Pat. No. 1,454,055. In the '055 device the blade edge is exposed without any type of guide or notch. This arrangement will almost certainly lead to a cutting of the material if attempted to be used with a ripping motion. One embodiment of Klamroth shows a guide having a round cross section. This guide, however, extends too far above and below the blade and thus renders it unsuitable for use as a seam ripper since it would be hard to force the blade to make contact with the stitching. Additionally, the guide is essentially hollow and fails to provide any means for separating the cloth from the stitch as the seam moves into the guide channel. Cloth and stitching would tend to bunch up in the channel resulting in severing of the cloth.
Thus, while all of the aforementioned references provide a cutter having a channel to guide a seam onto a blade, all suffer from one or more deficiencies which render the cutter either too slow or subject the fabric itself to the danger of being cut because the cloth sewn together at the seam is not sufficiently separated from the seam prior to engagement by the blade. None of the aforementioned references are capable of guiding the seam onto the edge of the blade while at the same time keeping the fabric away from the blade, such that the cutter may be rapidly moved along the seam with a smooth ripping motion.